<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS filters: Creating containing block for fixed positioned elements</title>
<link rel="author" title="L. David Baron" href="https://dbaron.org/">
<link rel="author" title="Mozilla" href="http://www.mozilla.org/">
<link rel="help" href="https://drafts.fxtf.org/filters-1/#FilterProperty">
<link rel="help" href="http://www.w3.org/2015/02/10-fx-minutes.html#action02">
<link rel="match" href="filter-containing-block-dynamic-1-ref.html">
<meta name="flags" content="dom">
<style>
  html, body { margin: 0; padding: 0 }
  #changefilter {
    position: absolute;
    top: 100px;
    left: 100px;
  }

  #abscovered {
    position: absolute;
    top: 50px;
    left: 50px;
    background: red;
    height: 100px;
    width: 100px;
  }

  #fixedmoves {
    position: fixed;
    top: 150px;
    left: 150px;
    background: green;
    height: 100px;
    width: 100px;
  }
</style>
<body>
  <div id="changefilter" style="filter: blur(4px)">
    <div id="abscovered"></div>
    <div id="fixedmoves"></div>
  </div>
  <script>
    var changefilter = document.getElementById("changefilter");
    var fixedmoves = document.getElementById("fixedmoves");
    var causeFlush = fixedmoves.offsetTop;
    changefilter.style.filter = "";
  </script>
</body>
